As it seems by now not only did Israeli jets entered Syrian airspace last week, they did probably carry out an air strike.
The question is what was the target? Weapons meant for Hezbollah in Lebanon? Or as Ha’aretz suggested a nuclear facility that Syria is building with the help of North-Korea.
According to Stratfor this is unlikely: 'Despite its status in U.S. eyes as a second-tier "Axis of Evil" state, Syria does not have a nuclear program that comes close to North Korea's or even Iran's program. It continues to focus on civilian research, particularly the production of radioisotopes for medical purposes. Though connections to Iranian and North Korean know-how could accelerate the Syrian program, Syria lacks the finances and resources to commit to an advanced nuclear program -- not to mention the standoff distance needed to conceal anything of that scale from the Mossad.
 Thus, whether the incursion was a photo reconnaissance, offensive strike or some other sort of mission, reports of the nuclear angle fail to convince. The rudimentary state of Syria's nuclear program (even taking into account all the unknowns) means Damascus has not crossed the sort of redline that would warrant the attention of what, by Syrian reports, appears to have been at least four Israeli aircraft.’